Telegraphic instrument



ZAMQM um. &, N ME L. L. DOW

TELEGRAPHIG INSTRUMENT 2 Sheets-Sheet 1 Filed Dec. 14:, 1948 m w m M 3 LAWRENCE L. DOW

Scam 394% L. L. DOW ZAWLWIL TELEGRAPHI C INSTRUMENT Filed Dec. 14, 1948 2 Sheets-Sheet 2 /|6 2O 29 IO 9 gvwonto'o LAWRENCE. L. DOW

, 55 fi I am Patented Sept. 6, 1949 Ti tsomrmc INSTRUMENT Lawrence 1L. Dow, Washington, 13. 6., assignor to The Dow-Key fiompoll fianad Winn pe M n t ba,

Ap l cati n D c mber 1 erase -m N 65.247

1-Glaim. 1

This invention relates to an improved telegraph key having the-novel capacity for use as a semi-automatic telegraph key at any angle suitable for, and selected by, the operator, and thus enable him to assume a more relaxed arm position and by so doing derive the benefits thereof.

Operators, long associated with the art, are subject to numerous muscular conditions in the operating a m due to the continued tension brought about by the cramped position necessary for operation of the fixed position, horizon-tally operated semi-automatic key. These muscular conditions are caused by contortion and improper use of the the operating arm. Maximum coordination and strength, because of the manner in which the arm muscles are rigged, is only obtained when the larger biceps are used in conjunction with the forearm muscles. The arm, in order to have control in the horizontal plane, sets reflex muscles against the weaker forearm flexor muscles, and control, with very limited strength, is obtained by muscular tension. It is this continued strain which finally so tires the reflex or flexor muscles, that one, usually the latter, becomes incompetent and complete loss of control results. Furthermore, the correct angle for relaxed operating motion with maximum control, is individual to each operator.

By my invention the operating position may be changed by rotating the entire keying assembly to any angle about an axis parallel with the base which the operator may select and thus increase the efficiency of the operator and remove the hazards which result from continuous muscular fatigue.

My invention is described in the following speciflcation with reference to the following drawings.

Figure 1 represents a top perspective view of my invention; Fig. 2 is an end view in perspective; Fig. 3 is a top view illustrating the vibrat ing section of my invention; Fig. 4 is a detailed top assembly view of the journal bearing and associate arms; Fig. 5 is a front view of the rear locking ring and associate screws; Fig. 6 is a front view of the bridge bearing member and associate journal lock screw; Fig. '7 is a front view of the conventional u spring.

The illustrated instrument is herein described with reference to the drawings and numbers thereon.

With particular reference to Fig. 2 and Fig. 3, operating lever II, to which handles l0" and I2 fiexor and reflex muscles of 2 are secured, is operated as a second class lever actuated by the thumb and forefinger of the right hand. Coupling I, being secured to said lever .11, is free to rotate about pivot pin '6 which serves as the fulcrum for said lever H and lever 2!. Travel of the said lever H is limited by the adjustable contact 15. When pressure is applied to handle 12, said lever ll moves away from lever 25 overcoming dash tension spring 14 causing .dash contact l5, which is secured to said lever ll, to make contact with adjustable contact l5. Return force for bringing said lever 'H to a position of rest against lever 2! is furnished by dash tension spring l4.

When pressure is applied to handle Ill, lever l'i actuates said lever 12l as a first class lever about their common fulcrum pivot pin 6. This pressure overcomes adjustable dot tension spring 22. said lever 2|, moving away from bumper screws 25 and 34, travels to a limit defined by the adjustment of bumper screw 23. This causes oscillation of the vibratable spring 21, said oscillations being transferred through dot spring holder 26 to the fixed dot spring 28, it being fastened thereto. Fixed dot spring 28, describing an oscillating arc, moves against adjustable contact screw 29 at the limit of its described arc.

To one versed in the art, the manner of keying a signal or sounder by means of a semi-automatic key will be understandable.

The novel feature of rotation is herein described with particular reference to Fig. 2 and Fig. 4. Journal bearing 20, having a front ring flange, supports two arms 30 and 33, opposite to each other on the flange diameter and parallel to the base 35. The said arms are secured to the said journal bearing flange as shown in Fig. 4. To the rear flange of journal bearing 20, said flange being the same diameter as the journal bearing surface, is secured a rear lock ring l8 which is secured to the said journal bearing 20 by the set screws 44 Fig. 5. Arm l1, supporting adjustable dash contact I5, is caused to rotate with the assembled journal bearing 2%) by being secured as shown in Fig. 4 to the rear lock ring l8.

Pivot pin 6, which supports, and is the fulcrum for operating levers H and 2|, is secured to the inside surface of journal bearing 20' and the assembled parts constitute a rotatable mechanism, the said journal bearing being completed by said rear lock ring and the said rotatable mechanism being supported above the base 35 by the bridge bearing 40.

In this manner the complete keying mechanism may be rotated and locked at any angle about an axis parallel with the base by lock screw [9 Fig. 5.

With the keying mechanism rotated for semiautomatic operation at any angle off the izontal plane, responsive and lag-free operation is possible by means of a vibrating section designed for this operation. See Fig. 3, and in particular dot contact spring 28 and dot spring holder 26.

Heretofore, the conventional dot spring assembly as shown in Fig. 7, has consisted of a U spring 60, providing support for contact 62, and secured to spring holder 64, said spring holder being drilled for mounting on the round vibrating arm 3| at a point directly opposite to adjustable contact 29. Positioning the said U spring at this point distant from the fulcrum which shifts to the extreme end of lever 2| when the vibrating section is in an oscillating condition, necessitates excessive weight in said vibrating section in order to overcome the damping effect of said U spring contact with adjustable contact 29. To ofiset this disadvantage, the said U spring is made exteremly flexible, resulting in poor contact characteristics.

In my invention, dot sprin holder 26, supporting dot contact spring 28, is secured on the vibratable spring 21 in such a position, adjacent to the established fulcrum, as to give a greater mechanical advantage. Owing to this increased leverage, the damping effect of dot spring 28 is greatly reduced and consequently said dot spring 28 can be much more rigid. The reduction in required force necessary for vibration with firm dotting characteristics, reduces the amount of mass required in the vibrating section. This reduction is effected by the use of lighter material for vibrating arm 3| and speed control weight 32.

By the method described herein, satisfactory oscillation is obtained in any plane from the horizontal to the vertical and a variety of speeds is obtained by shifting the position of speed control weight 32 on vibrating arm 3 I.

I am aware that prior to my invention, telegraph keys have been made to provide semiautomatic operation and also that various adjustable hand lever keys have been presented.

I do not therefore claim these broadly.

I claim:

In a telegraph key, a base, a journal bearing, said journal bearing being provided with a suitable locking device for fixing position at any angle about an axis parallel with the base and said journal bearing being provided with two arms parallel to the base and a flange for securing an additional ring, said ring in combination with the journal bearing, provided with three arms carrying adjustable contacts, adjustable bumper screws, and adjustable tension springs which rotate simultaneously with operating levers and vibrating section on a bearing securedto said base, maintaining contact alignment between contacts by said levers being fulcrumed in said journal bearing, the combination providing semi-automatic operation at any desired angle about said axis parallel to said base.

LAWRENCE L. DOW.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Lytle Feb. 12, 1924 

